Fair Value Measurements - Additional Information (Details) - USD ($) shares in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Nov. 30, 2018	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets, Level 1 to Level 2 transfers amount		$ 0	$ 0
Fair value assets, Level 2 to Level 1 transfers amount		0	0
TSG
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Agreement period	20 years
Number of common shares received under agreement	1.1
Additional value of common shares receivable under agreement upon exercise of first option by TSG	$ 5,000,000.0
Number of initial common shares received under agreement restricted	1.1
Restriction expiration month and year on transfer that may not be sold	2019-11
Common shares, sales restriction period, upon exercise of first option	1 year
Recognized revenue		$ 300,000	$ 1,000,000.0
TSG | William Hill US
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Proceeds received from selling TSG shares		50.00%	50.00%
Accrued Other Liabilities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Acquisition related contingent considerations		$ 400,000	$ 400,000	$ 500,000
Accrued Other Liabilities | TSG | William Hill US
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Estimated obligation		7,900,000	7,900,000
Restricted Cash and Investments | TSG
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value, total		15,800,000	15,800,000
Other Long Term Liabilities | TSG
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Deferred revenue		$ 17,700,000	$ 17,700,000